Last visit was: 22 Sep 2026, 22:25 It is currently 22 Sep 2026, 22:25
Decision Tracker
My Rewards
New comers' posts
New posts
Unanswered

Close

GRE Prep Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GRE score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Go to My Error Log Learn more
Close

Request Expert Reply

Confirm Cancel
PREVIOUS TOPIC
NEXT TOPIC

The heights of boys in a schools are normally distributed. B

Tags :
Find Similar Topics  About  Add a Tag

Show Tags
Hide Tags

avatar
KomalSg
Intern
Intern
Joined: 12 Nov 2017
Posts: 30
Own Kudos [?]: 57 [31]
Given Kudos: 0
Send PM
The heights of boys in a schools are normally distributed. B [#permalink] New post   07 May 2020, 23:56
5
26
Bookmarks
00:00

Question Stats:

35% (01:24) correct 64% (01:00) wrong based on 219 sessions

Hide Show timer Statistics

The heights of boys in a school are normally distributed. Boy1's height is at 80th percentile. Boy2's height is at 20th percentile.

Quantity A
Quantity B
Percentage of students whose heights are less than or equal to Boy 1's height
Percentage of students whose height are more than Boy 2's height.


A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.
ShowHide Answer
Official Answer
A
Most Helpful Community Reply
User avatar
P
GreenlightTestPrep
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Own Kudos [?]: 12834 [11]
Given Kudos: 136
Send PM

Top Member of the Month
Re: The heights of boys in a schools are normally distributed. B [#permalink] New post   09 May 2020, 06:05
6
5
Bookmarks
KomalSg wrote:
The heights of boys in a school are normally distributed. Boy1's height is at 80th percentile. Boy2's height is at 20th percentile.

Quantity A
Quantity B
Percentage of students whose heights are less than or equal to Boy 1's height
Percentage of students whose height are more than Boy 2's height.


A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.


Would the answer be C or A?


Let's say there are 100 students in the school.

If Boy 1's height is in the 80th percentile, then if we arrange all of the heights in ascending order, Boy 1's height will be the 81st value.
Since 80 heights are less than Boy 1's height, this means Boy 1's height is in the 80th percentile.

If Boy 2's height is in the 20th percentile, then if we arrange all of the heights in ascending order, Boy 2's height will be the 21st value.
Since 20 heights are less than Boy 2's height, this means Boy 2's height is in the 20th percentile.

Quantity A: Percentage of students whose heights are less than OR EQUAL TO Boy 1's height
If we arrange all of the heights in ascending order, Boy 1's height will be the 81st value, which means there are 81 students whose heights are less than or equal to Boy 1's height.
In other words, 81 percent of students have heights that are less than or equal to Boy 1's height.

Quantity B: Percentage of students whose height are more than Boy 2's height.
Important: Quantity A featured the words "or equal to," whereas Quantity B does not have those same words.
If we arrange all of the heights in ascending order, Boy 2's height will be the 21st value.
100 - 21 = 79. So, there are 79 students whose heights are greater than Boy 2's height.
In other words, 79 percent of students have heights that are greater than Boy 2's height.

Answer: A

Cheers,
Brent
General Discussion
User avatar
D
Carcass
Verbal Expert
Joined: 18 Apr 2015
Posts: 36175
Own Kudos [?]: 43383 [0]
Given Kudos: 27262
Send PM
Re: The heights of boys in a schools are normally distributed. B [#permalink] New post   09 May 2020, 02:44
Expert Reply
Please follow the rules how to format a question.

https://gre.myprepclub.com/forum/how-to-po ... 12752.html

We appreciate your efforts.

Regards
avatar
Nikhil4GRE
Manager
Manager
Joined: 29 Apr 2020
Posts: 67
Own Kudos [?]: 10 [0]
Given Kudos: 0
Send PM
Re: The heights of boys in a schools are normally distributed. B [#permalink] New post   09 May 2020, 03:53
Is it the kind of percentile math? I think the answer would be C.
avatar
safana
Intern
Intern
Joined: 01 May 2020
Posts: 31
Own Kudos [?]: 15 [4]
Given Kudos: 0
Send PM
Re: The heights of boys in a schools are normally distributed. B [#permalink] New post   12 May 2020, 11:41
2
1
1
Bookmarks
Here, the trap is in the wording of the question. In quantity A they mention 'equal to or less than' while in quantity B they mention 'more than' (not including the 20th percentile). So choice A>B. if the quantity B said more than or equal to then the answer would have been choice C.
avatar
sarthak3142
Intern
Intern
Joined: 16 Aug 2022
Posts: 2
Own Kudos [?]: 3 [2]
Given Kudos: 1
Send PM
Re: The heights of boys in a schools are normally distributed. B [#permalink] New post   18 Aug 2022, 00:13
2
safana wrote:
Here, the trap is in the wording of the question. In quantity A they mention 'equal to or less than' while in quantity B they mention 'more than' (not including the 20th percentile). So choice A>B. if the quantity B said more than or equal to then the answer would have been choice C.


if Quantity B mentions 'greater than or equal to', shouldn't the answer be 'D' ?
Since,
(i) it is not mentioned that all boys have distinct heights
and
(ii) we also do not know how many boys have the same height as either Boy1 or Boy2

Please Help!

Thank you.
avatar
B
Paul121
Manager
Manager
Joined: 19 Jun 2021
Posts: 52
Own Kudos [?]: 30 [0]
Given Kudos: 24
Send PM
Re: The heights of boys in a schools are normally distributed. B [#permalink] New post   22 Oct 2022, 13:34
GreenlightTestPrep wrote:
KomalSg wrote:
The heights of boys in a school are normally distributed. Boy1's height is at 80th percentile. Boy2's height is at 20th percentile.

Quantity A
Quantity B
Percentage of students whose heights are less than or equal to Boy 1's height
Percentage of students whose height are more than Boy 2's height.


A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.


Would the answer be C or A?


Let's say there are 100 students in the school.

If Boy 1's height is in the 80th percentile, then if we arrange all of the heights in ascending order, Boy 1's height will be the 81st value.
Since 80 heights are less than Boy 1's height, this means Boy 1's height is in the 80th percentile.

If Boy 2's height is in the 20th percentile, then if we arrange all of the heights in ascending order, Boy 2's height will be the 21st value.
Since 20 heights are less than Boy 2's height, this means Boy 2's height is in the 20th percentile.

Quantity A: Percentage of students whose heights are less than OR EQUAL TO Boy 1's height
If we arrange all of the heights in ascending order, Boy 1's height will be the 81st value, which means there are 81 students whose heights are less than or equal to Boy 1's height.
In other words, 81 percent of students have heights that are less than or equal to Boy 1's height.

Quantity B: Percentage of students whose height are more than Boy 2's height.
Important: Quantity A featured the words "or equal to," whereas Quantity B does not have those same words.
If we arrange all of the heights in ascending order, Boy 2's height will be the 21st value.
100 - 21 = 79. So, there are 79 students whose heights are greater than Boy 2's height.
In other words, 79 percent of students have heights that are greater than Boy 2's height.

Answer: A

Cheers,
Brent


Sorry if it is a repeating question, but it is something that always confuses me.
If there are 100 students. Why the 80th percentile student is the 81 student and not the 80 student?
I assume it is because of the even/odd area, but maybe you can explain it in a better way?
Thanks!
User avatar
bumpbot
GRE Prep Club Legend
GRE Prep Club Legend
Joined: 07 Jan 2021
Posts: 6099
Own Kudos [?]: 87 [0]
Given Kudos: 0
Send PM
Re: The heights of boys in a schools are normally distributed. B [#permalink] New post   12 Dec 2024, 02:55
Hello from the GRE Prep Club BumpBot!

Thanks to another GRE Prep Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
Prep Club for GRE Bot
gmatclubot
Re: The heights of boys in a schools are normally distributed. B [#permalink]
12 Dec 2024, 02:55
Moderators:
adewale223
GRE Instructor
166 posts
bronaugust
GRE Forum Moderator
37 posts
VibhuAnurag
GRE Instructor
275 posts
Nsp10
Moderator
45 posts
tyrant100
GRE Forum Moderator
144 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Main navigation

Partners

GRE Resources

www.ets.org/gre | About | Terms and Conditions and Privacy Policy | Prep Club for GRE Rules | Contact | Advertise